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Study into Public Health Risks of ESBL E. coli

UK - A new study will, for the first time, establish the most significant reservoirs of a strain of antibiotic resistant bacteria known as ESBL-positive E. coli that cause human illness in the UK.

The findings of the research by Public Health England (PHE) and funded by the Department of Health will help to develop intervention strategies in efforts to reduce the numbers of infections such as urinary tract infections or blood poisoning, caused by these bacteria.

The research is being led by PHE with key collaborators from the Animal Health and Veterinary Laboratories Agency, The University of Cardiff, The University of East Anglia, The University of Glasgow, Queen Mary University of London, and Health Protection Scotland.

The study will look at sewage, farm slurry and raw meat to determine whether there are any potential risks to human health in a number of different reservoirs of these bacteria.

It will also look at stool samples from patients who have no symptoms of illness (asymptomatic carriage) to see whether the bacteria is in their gut (colonisation).

E. coli is a bacterium that lives in the guts of humans and many other animals. Colonisation of the gut by E. coli is perfectly normal and is harmless, although some other types cause diarrhoea. However, E. coli is also the commonest cause of urinary tract and bloodstream infections, which usually require antibiotic treatment.

Not all types of ESBL-positive E. coli bacteria cause human disease, and the contribution to human disease made by resistant strains from animals, meat and environmental sources is not well understood.

Resistant strains of E. coli are an increasing problem, reducing the number of antibiotics that a doctor can use for treatment. Many of the resistant strains produce enzymes called ESBLs (Extended-Spectrum Beta-Lactamases), which make them resistant to most penicillin-like antibiotics. E. coli with ESBLs can also be found in food animals, raw retail meat, sewage and river water, but whether these reservoirs pose any public health risk is poorly understood.

Professor Neil Woodford, Head of the Antimicrobial Resistance and Healthcare Associated Infections Reference Unit at PHE, said: “The risks posed to human health by resistant E. coli from non-human reservoirs are not fully understood. This study will help to disentangle this complex interrelationship.

“Treatment of infections caused by resistant E. coli can be difficult, which is why we need to understand the risks better.

“Having said that, we want to reassure the public that presence of these bacteria in the gut does not require antibiotic treatment and is usually temporary.

“Most colonised people never develop an infection caused by the resistant strain.

“This study is very important because its results will help to shape future intervention strategies to reduce the spread of these antibiotic-resistant strains of bacteria and to reduce the numbers of infections that they cause.”